1. Field of the Invention
The present invention relates to a semiconductor device which has a structure that a semiconductor IC chip and an external electrode terminal are connected through a loop-like wire formed by wire bonding, a method of manufacturing the semiconductor device, and a wire bonding method.
2. Description of the Related Art
Various methods have been suggested to produce an electrical connection between an electrode pad of a semiconductor IC chip and an inner lead by wire bonding, at manufacturing a semiconductor device, in Japanese Patent Kokai Publication No. 2008-117888 (Patent Document 1) and Japanese Patent Kokai Publication No. 2008-34567 (Patent Document 2), for example. FIG. 13 illustrates a typical wire bonding method which has the steps of: bonding a gold ball 5 to an electrode pad 4 of a semiconductor IC chip 3, which is fixed on a die pad 1 with an adhesive agent 2, by using a wire bonding apparatus (not illustrated in the drawing), forming a loop-like wire 6 so that a neck (a part standing straight) 6a of a predetermined length H6a is formed in a direction of right above a top 5a of the gold ball 5, and extending the wire to the inner lead 40 and bonding the extended loop-like wire 6 to an inner lead 40.
However, in the wire bonding of the conventional manufacturing method, it is necessary that the length H6a of the neck 6a of the loop-like wire 6 is considerably long in order to reduce stress occurring at the top 5a of the gold ball 5. For this reason, the conventional semiconductor device which includes the semiconductor IC chip 3 and the loop-like wire 6 has the following problem that: it is difficult to reduce a height H6 of the loop-like wire 6 sufficiently, and thus the semiconductor device cannot be sufficiently reduced in thickness.